<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    const a = 10;
    const b = 2;

    const sum = a + b;
    const difference = a - b;
    const product = a * b;
    const quotient = a / b;

    console.log("Сложение: " + sum);
    console.log("Вычитание: " + difference);
    console.log("умножение: " + product);
    console.log("деление: " + quotient);
</script>
</body>
</html>